Safety lamp lock



April 1929. R, g, MRE 1,710,373

SAFETY LAMP LOCK Filed Feb. '7, 1928 Patented Apr. 23, 17929;

Unirse STATES PATENT OFFICE/ ROBERT A. MOORE; orv NEW YORK, N.QY., AssIGNoR 'ro MULTrrLE sELLrNe oonronn! THON, E NEW YORK, N. Y.

SAFETY LAMP Loox. Y

T his invention relates to safety lamp locks. Une object of this invention is to provide an improved device to lock a lamp in its socket and prevent unintended or unauthorized removal of the same.V

Another object oftheinvention is toprovide a device of the character described in whichimproved means permits the said device to' be unlocked. .I p

A further obj ect of the invention is the provision of a device of the type speciiied which includes a member having bitingengagement between the socket and the lamp base, for the purpose set forth.

A still further obj ect of the invention 1s the production ofa device of the class described, i which can be made as a simple stamping having improved coaction withy the socket and lamp base. Y p Still another object of lthe invention is to furnish a device of the species Vmentioned which is neat and inconspicuous, so as to' be inaccessible for unlocking except by a particular key or means; and which is of properly insulated character; and is reliable and etlicient to a high degree in use.

`With the foregoing and other objects in view the invention consists in the arrangement f and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein,'still for the purpose of illustrating' a practical embodiment thereof reference is had to the accompanying drawings in which like reference characters designate the same parts in the several views, and inwhich- Figure 1 is a view in elevation of a. lampl and socket assembly showing in section an embodiment of the invention in unlocked position. l.

Fig. 2 is anenlarged sectional view taken on the line 2 2 of F ig.` 1.

Fig. 3 is a fragmentary view similar to Fig. 1 of the device in locked position.

Fig. Ll is an enlarged sectional view'taken on the line 4 4 of Fig. 3.

Fig. 5 is an enlarged sectional detail view of the device in locked position.

Fig. 6 is a perspective detail view of a member embodying the invention.

Fig. 7 is aI diagrammatic view showing the action of the locking member.. l y J Figs.A 8 and 9 are fragmentary detail views of modifications of the invention.

Referring in detail-to the drawing,l10 denot-es a lamp and 11 va socket, in conjunction with which this invention is embodied. The lamp is seen to comprise the usual screw base 12, having the end and shell contactsl and 14 respectively. Coacting with these, the sockethas central and shell contacts 15 and 16. Between the shell 16 and the casing 17 of the socket, is inserted the usual sleeve of insulation 1l l Associated in an improved manner between .the .contact shells of the socket and lamp base is a ylock .19 embodyingthe invention." This lock is of flat cross section and circular in for; mation, and can be'made of'various materials, as, for example, steel or a softer metal. Preferably, the lock is made as a stamping bent to the desired form. ness, the same can be readily slipped into place in the socket without in any Way interfering with the insertion of 'the' lamp base thereinto', and its narrowness permits it to be sprung in a direction widthwise of the metal for releasing the lock as hereinafter described.

The device 19 includes afholder portion 2O having at its ends the lugs 21 which extend in the same direction and lie in the cylindrical surface defined by the device19. Offsetat 22 inthe opposite direction is the shank portion vice seats on the exposed edge of the insula? tion 18 as shown in Fig. 3. The reti-actor 26v is insulated preferably by immersing in a bath of liquid insulating material and drying thereafter.y n

The locking member 25 is offset inward of the lock 19 as shownat 28 to be adapted to lie within the socketshell 1 6. It is also of transverse angularity with respect to the adjacent shank portion 24;, and of ogee form, so that its side edges29 and 30 are directed respectively inward and outward; The said edges are, likewise7 comparatively thin, and the end 31 of the'l locking member is beveled down toward the edge 80 for a purpose hereinafter described.

In practice the device 19 is inserted coaxially into the socket, with the lugs 21 leading Being of sufficient thin- Y easily over the inclined, inner tace ogt the locking member 25. rlilhe retractor 2'? is new small and inconspicuous at the side o1' the lamp.

Should an unauthorized person attempt to unscrew the lamp, thelockingmember 25 will bite at its edges 29 and 3() into the lamp and socket shells 14 and 1G respectively, and prevent the lamp from being stolen. To this end the acute corner at the intersection of the edges 29 and 3l oi the locking member will cooperate byv insu-ring an immediate grip et the salty device on the lamp base.

"llo open the locking device 19, a key adapt* ed to engage the lug 2'?, is used to draw the retractor 2G, 'and release the locking member 25. The said key may be oli any suitable eonstruction and is therefore not shown. It will be understood `that the shank 23 is sprung widthwise to release the locking member, and the latter is then positioned directly between the insu-lation 18 and the shell 11i, and beyond `orbelow the shell 16. The lamp can now be unscrewed from the socket in the usual manner.

The device 19 can not lbe released except with a proper key provided ior the purpose. According to the construction of this invention, when a lamp has bee l screwed into its socket, the device .19 adjacent to the locking member will be trictionally engaged with sufficient tightness to prevent the retractor from being operated except by the key attoresaid.

Fig. 8 illustrates a modification ot the invention, wherein the retractor 25 terminates in an eye portion 32, which is straight therewith, and extends alongside the lamp 10. The eye portion is small. and inconspicuous, and is insulated by immersion in a solution oit insulating liquid, that dries `to torm a coating thereon.

l? 9 illustrates a modilied retractor 25 that is straight throughout and weakened at a series of notches 33.- Should the depth of the lamp socket be less than usual, a portion of the retractor can be cut oil at a notch to shorten the same to suit. The length of the retractor projecting from the socket may be thus maintained constant for all lamps.

lt is thus seen that I have provided a device which i'ullills the several objects of the lt is to be understood that within the scope et the invention, the term .lamp base iiicludes plugs and similar screw devices.

The invention contemplates the obvious application oit the looking member 25 to all male and Vtemale interengaging screw members, as the ltuli equivalent oi the lamp base and socket.

l claim:

1.' ln combination, a lamp base, a socket l'iaving screw engagement therewith, andv a device to lock the lamp base against removal from the socket, said socket having an outer metallic wall, a sleeveoil insulation therein, and a Contact shell in the said sleeve,rsaid Contact shell terminating in spaced relation to the outer end of the said sleeve, said device including an: anchor portion engaged between the aid shell and the said sleeve, an armextending from said anchor portion: and overlying the outer end of' the con-tact shell, said arm having a locking member between the contact shell and the lamp base, said locking member extending angularly from the arm in thegeneral direction of the axis of the lamp base, saidl member having its opposite edges sharp, said edges lying along an angle with the tangent to thelamp base to cause the said edges to' bite into the lamp base andthe contact shell to prevent removal oi'A thev lamp, and means to spring said arm to move the locking .member out of engagement between the lamp base andy the Vcontact shell.

2. ln combination,` a lamp base, a socket having screw engagement therewith, and a device to lock the lamp base lagainst removal vfrom the socket, said socket having an outer metallic wall, a. sleeve ot insulation therein,

anda contact shell in the said sleeve, saidcontactshell terminating in spaced relation tothe outer end of the said sleeve, said device including'an anchor portion engaged between the said shell and the said sleeve, an arm eX- y tending from said anchor portion and over lying the outer ond. of the contact shell, said arm having a locking member between the contact shell and the lenipbase, said locking member extending angularly from the arm in the general direction oi the axis oit the lampV base, said men'iber having opposite edges sharp, said edges lying 'along an angle with the tangent to the lamp base to cause the said edges to bite into the lamp base and the con-A tact shell to prevent removal ot the lamp.

3. The combination as set forth in claim 1, wherein said device is made of ajsingle piece ot llat sheet metal.

4l. rlhe con'ibination as set forth in claim 1, wherein said device is made oiI a piece off flat sheet metal, and a plurality otanehor portions are provided ailording engagement over av large angle, said vportions'being connected iby an arcuate member, said .arm being of arcuate form and extending with the locking member in proximity to the end anchor portion.

5. As an article of manufacture, a device for locking a lamp base against unscrewing from a socket, said device including an arcu- .ate anchor member, an arcuate arm extending fromone end of the anchor member andhav` ing substantially the same axis, `a locking member projecting from the free end of said arm in the direction of said axis, said locking member having opposite edges formed to constitute cutting edges, said cutting edgeslying at an angle with the tangent to the arm to bite into the lamp base and into the socket.

6. As an article of manufacture, a device for locking a lamp base against unscrewing from a socket contact shell, said device in- Y cluding an arcuate carrier member and a locking member, said locking memberhaving its opposite edges formed to constitute cutting edgeslying at an angle with the tangent to the carrier member.

7. As an article of manufacture, a device for locking a lamp base againstV unscrewing from a socket, said device including an arcuate carrier member, and a substantially Hat narrow locking member made of thin mate rial, said locking member having its opposite edges constituting cutting edges lying at an angle with the tangent to the carrier member.

8.-As an article of manufacture, a device for locking a lamp base against unscrewiiig from a socket, said device including arcuate carrier means, and a narrow locking. member made of thin metal, said locking member extending substantially in the direction of the axis of said carrier means and having its opposite edges constituting cutting edges, said cutting edges lying at an angle with the tangent to the carrier means to bite into the lamp base andthe socket.

9. In combination, a lamp base, a socket having screw engagement with the lamp base, and a device to lock the lamp base against re moval from the socket, said device including a narrow locking member of thin material lying betweenthe lamp base and the wall ofl the socket, said locking member having itsv opposite edges lying along an angle with the tangent to the socket constituting cutting edges, one of the edges biting into the vlamp base and the other into the wallof the socket.

10. In combination, a lamp base, a socket having screw engagement therewith, anda device to lock the lamp base against removal from the socket, said device being made of a piece of thin sheet metal, said device having arcuate anchor means lying between the lamp posite cutting edges lying along an angle to Y bite into the lamp base and into 'the contact Y.

shell.`

11.In combination, a lamp base, a sockety having screw engagement therewith, and a device to lock the lamp base against removal froin'the socket, said socket having a Contact shell, said device having ay narrow locking member between the lamp` base yand the contact shell, said locking meinberextending in the general 'direction' of the axis of the lamp base,'and resilient means carrying said locking member, said locking member having cutting portions angularly disposed to bite into the lamp base and socket.

12. In combination, a lamp base, a socket having screw 'engagement therewith, anda device to lock the lamp base against removal from thesocket, said socket having a Contact shell, said device having a narrow lockingmember between the lamp base and the con-l tact shell, said member having angularly disposed cutting edges to bite into the socket and the lamp base and the contact shell having any gularly disposed edgesbiting intothe lamp base and into the contact shell, said biting action being made effective on attempting tounscrew the lamp base from the socket.

14. A construction as set forth in claim 13, wherein the first mentioned means is of ogee form to provide the said edges.

15.- The combination with male and female interengaging screw y members, ofV a narrow locking member made of thin materiah'said locking member lying between the screw'walls of the said interengaging screw members, said locking member having its opposite edges lying along an angle' with the tangent to the said interengaging members to cause said edges to bite into said interengaging members to prel vent unscrewing ofthe same, and means to ROBERT A. MOORE. 

